Manufacturing steps of various products include a mixing process for uniformly mixing a plurality of fluid materials. As one example, in the manufacturing steps of a coating material, raw materials containing several types of coloring materials or pigments are mixed at a specific ratio in order to obtain a product having a desired color tone so that a color tone of a final product is obtained. In such a case, although it may be thought that when a product having the same color tone is produced again, predetermined raw materials are mixed at the mixing ratio identical to that at the previous time to obtain the same product, since the raw materials themselves actually have variations such as slightly different concentrations per lot, the final product having the color tone completely matched with that at the previous time cannot be obtained only by mixing at the predetermined mixing ratio. Conventionally, in compounding such coating materials, after they are once mixed at the predetermined mixing ratio, the color tone of the product is checked and then several raw materials are additionally put into a mixing tank according to the result thereof and agitated again to manufacture a coating material completely matched with a desired color tone.
However, in the above conventional technique, in the case of using commercially available coating materials, as can be easily imaged from that the materials are diluted for coating at an appropriate concentration by adding a solvent such as a reducer, a raw material having a remarkably high concentration and high viscosity has to be treated in a stage of mixing coating raw materials. Even when a plurality of fluid materials having a high viscosity are put into and agitated in the mixing tank, they have required a long agitating time to be uniformly mixed in a complete manner. Additionally, as described above, since it is required that after the agitating step is once terminated, the raw materials are additionally put into and agitated in the mixing tank for fine adjustment of the color tone, the agitating time is further made longer.
Further, as user's needs therefor have been increased in recent years, there exists a need for coating materials having various color tones as compared with conventionally in the coating material business. For example, dozens of coating materials having slightly different color tones are required to compound for white coating materials. Naturally, experiences and information on the compounding at the previous time are effectively reused so that a time for fine adjustment of color tones is omitted, but when a coating material having a novel color tone is ordered to manufacture from an automobile manufacturer, trial and error are required to repeat to a certain degree.
Furthermore, there is required that various coating materials are small produced depending on various user's needs. As described above, when brightness of colors is slightly different even in the same color tone, various types of coating materials are required to mix. After several coating materials having certain color tones are mixed, if a mixer such as a mixing tank or an agitating vane is not completely washed, it influences the color tones of the coating materials to be manufactured in the next step. The agitating device of the mixer for coating materials has a complicated shape and structure in order to agitate the raw materials having a high viscosity as efficiently as possible. A large quantity of human efforts is required for completely washing the agitating device or the mixing tank for each small-producing.
Therefore, it is an object of the present invention to provide a mixer capable of uniformly mixing a plurality of fluid materials without a mixing tank or an agitating vane.